Magnetic chuck



(No Model.)

0. S. WALKER. lMAGNETIC CHUCK No. 564,296. .Patented July 21, 1896.

UNITED STATES PATENT OFFICE.

OAKLEY S. XVALKER, OF VORCESTER, MASSACHUSETTS.

MAGNETIC CHUCK.

SPECIFICATION forming part of Letters Patent No. 564,296, dated July 21, 1896.

Application filed February 13 1896. Serial No. 579,147. (No model.)

To all whom, it may concern:

Be it known that I, OAKLEY S. VALKER, a

citizen of the United States, residing at Worcester, in the county of lVorcester and State of Massachusetts, have invented a new and useful Magnetic Chuck, of which the following is a specification.

My invention relates to magnetic chucks or holders for iron or steel pieces that require to be held firmly while being machined, filed, carved, or otherwise operated upon, and is more particularly adapted for thin 4flat pieces that require to be held down firmly and from their nature cannot be held by their edges without interfering with the machining or other operations to be performed. Furthermore, the gripping of pieces by their edges in a vise or with other ordinary appliances has a tendency to lift the piece in a certain degree.

The object of my invention is to provide a holder that will insure the piece held thereon being in close and firm contact with the holder itself and obviate the necessity of any other than magnetic means for holding the same.

The difficulty with magnets for holding work heretofore has been that while the force has been usually ample to hold down the work or pieces placed thereon, the same could be moved about quite easily in a circular direction; and, furthermore, the distribution of power, or lines of greatest force, over the face or poles of the magnet has been limited. In my invention l obviate both ofthese difficulties and provide magnetic means for preventing the twisting or swiveling about of the work, and improved means of distributing the magnetic force over the face of the magnet or holder.

Referring to the accompanying drawings, like letters of reference indicating like parts in each, Figure l is a part plan and part sectional view of my invention; Fig. 2, a transverse section through line d b of Fig. l. Fig. 3 is a part elevation and part longitudinal vertical section; and Fig. 4 is a partial perspective view of the magnet-core- A is the central core of the magnetic chuck, formed of cast metal, and is provided at the bottom with a rectangular flange A and at the top with a sinuous or angular flange A2, the whole forming an oblong spool for the reception of the inagnetizing coil E. En'- circling the central core and coil is the oblong shell B,resting upon and fastened to rectangular flange A by the screws B. The top of the shell B is provided with an aperture similar in shape to the flange Awhich passes completely through the shell B or flush with the outer surface of the same. A narrow space, however, is left between the flange and shell, which is filled with non-magnetic material C, the iiange A2 forming one pole of the magnet and the top face of the shell B forming the other, and a narrow air-gap only remains to complete the magnetic circuit. It will be noticed that the angularA iiange A2 in its zigzag course extends the air-gap or line of maximum power of the magnet until it has crossed the greater part of the surface of the chuck, and .a more even pressure will thus be exerted on a piece of work laid thereon. Adjustably attached to the top surface of the shellB is the slotted magnetic strip D, fastened by the screws D', and so placed that one edge D2, Figs. l and 2, of the said strip crosses or passes in close proximity to a portion of the air-gap. A piece of work now being placed in contact with the edge D2 of strip D and resting on the top surface of the chuck will be strongly attracted to the Strip as well as to the shell B, and the piece will be more firmly held in place, and the tendency to twist about under the pressure of the tool is obviated. Terminals E' E2 of the coil E pass out through a suitable aperture in the end of the shell B and may be suspended from the electric supply mains from overhead in long loops capable of a swinging action when the chuck is moved; as, for instance, when the same is used on a metalplaner. lt will be noticed that the projections B3 of the shell B extend over the central core A of the spool.

By reference to Figs. 2 and l it will be seen that the core A is cut away at A3 to such a depth that a wider air-gap is formed under the said projections than is formed at the surface of the holder. This is to prevent undue leakage of the lines of force.

It is evident that other forms of magnets could be employed for magnetic chucks with various shapes and contours of air gaps to distribute the magnetic power, also that a ICO plurality of magnetic strips Could lie einpleyed to assist in holding the Werl: in place, I theiefere do not @Online myself te et sinu- Ons oi' angular eeui'se foi? said gap, el to asingle auxiliary inztgiletie strip fmsteztdying locking' zigzag' 01.' sinneus conteurs sul staintially as described.

2. The combination with t chuck, V01.' heldin;l work t0 be nmehined mfetlieiwise manipulated, el. magnetic I'iolmf Mees :1nd :in nfl,- justa'bie magnetic sti-ip er bm: the edges el' Wliieli felini a. raised suilfaiee limn the chuckifztee le extend the :ietou ei ille nmgnetie lines it mi ingle te the face eli' the cimeli sulristzlntiaily as set 'foi-th.

- (LkKLEY WALKER. lVitnesses:

IB. lf. CURTIS, J'. NV. ROBERTSON. 

